Gas logging experimental device and method based on flow state of drilling fluid in borehole

Abstract

The invention belongs to the field of petroleum and natural gas logging engineering, particularly relates to a gas logging experimental device and method based on the flow state of drilling fluid in a borehole, and aims to solve the problem that in the prior art, the influence of the flow state of the drilling fluid on gas logging data cannot be analyzed. The device comprises a drilling fluid injection module, a drilling fluid flow state excitation module, a gas sample injection module and a data processing module, the drilling fluid injection module is used for injecting drilling fluid into a well annulus; the drilling fluid flow state excitation module is used for exciting a laminar flow or turbulent flow drilling fluid flow state; the gas sample injection module is used for simulating the uniform gas inlet process of a gas sample along the well circumference; the data processing module is connected with the drilling fluid flow state excitation module, and the data processing module is used for performing gas logging analysis, degassing and recycling treatment on the upward-returning drilling fluid. According to the invention, drilling fluid states under different conditions are simulated, different drilling fluid flow states are realized in a borehole, and the influence of the drilling fluid flow states on gas logging data can be analyzed.

Description

Technical Field

[0001] The invention belongs to the field of petroleum and natural gas logging engineering, and in particular relates to a gas logging experimental device and method based on the flow state of drilling fluid in a wellbore. Background Art

[0002] Gas logging is a key technology in the development of oil and gas reservoirs. This technology displays reservoir oil and gas information by analyzing the hydrocarbon gas content in the returned drilling fluid. However, the content of hydrocarbon gas in the returned drilling fluid is affected by many factors, such as drilling fluid parameters (density, viscosity, temperature), drilling fluid flow state, bottom hole pressure fluctuations, etc., which interfere with the accuracy of gas logging to a certain extent. Among the above factors, the impact of drilling fluid flow state on gas logging has not been discussed. Drilling fluid flow states can be divided into laminar flow and turbulent flow. Different flow states will affect the migration of hydrocarbon gas in the wellbore, resulting in distortion of gas logging data. In view of this, it is urgent to develop a gas logging experimental device and method that takes into account the flow state of drilling fluid in the wellbore to obtain the influence of drilling fluid flow state on gas logging data.

[0003] Through literature research, some gas logging experimental devices have been developed at this stage to discuss the impact of different factors on gas logging data. For example, the patent with application number: CN201720060698.5, the invention name: A downhole gas logging test device while drilling, the patent with application number: CN201910717334.3, the invention name: A Fourier infrared gas logging method and device patent, the application number: CN202011123186.1, the invention name: A gas logging data detection device simulating the wellbore environment, none of them can realize different drilling fluid flow states in the wellbore, and it is impossible to analyze the impact of drilling fluid flow states on gas logging data.

[0004] Based on this, the present invention provides a gas logging experimental device and method based on the flow state of drilling fluid in the wellbore. Summary of the invention

[0005] In order to solve the above-mentioned problem in the prior art, that is, in the prior art, different drilling fluid flow states cannot be achieved in the wellbore, and thus the impact of the drilling fluid flow state on the gas logging data cannot be analyzed, the present invention provides a gas logging experimental device and method based on the drilling fluid flow state in the wellbore.

[0006] In a first aspect, the present invention provides a gas logging experimental device based on the flow state of drilling fluid in a wellbore, the device comprising a drilling fluid injection module, a drilling fluid flow state excitation module, a gas sample injection module, and a data processing module;

[0007] The drilling fluid injection module is used to inject drilling fluid into the wellbore annulus;

[0008] The drilling fluid flow state excitation module comprises a first magnet, a second magnet and a metal partition connected to the drilling fluid injection module; based on the magnetic force of the first magnet and the second magnet, the metal partition is moved to excite the laminar or turbulent drilling fluid flow state;

[0009] The gas sample injection module is fixed below the drilling fluid flow state excitation module, and is used to change the rock formation permeability through the gas sample injection structure, and to simulate the uniform gas intake process of the gas sample along the wellbore, thereby simulating the process of hydrocarbon gas infiltration into the wellbore annulus;

[0010] The data processing module is connected to the drilling fluid flow state excitation module, and the data processing module is used to perform gas measurement analysis, degassing and recovery processing on the returned drilling fluid.

[0011] In some preferred embodiments, the drilling fluid injection module includes a preparation box, a valve, a fluid delivery pipe, a first booster pump, a drill string, a drill bit and a well wall;

[0012] The preparation box is used to prepare and store drilling fluid. The preparation box is sealed and fixed to and connected with one end of the infusion pipe. The other end of the infusion pipe is arranged in the drill string through the first booster pump. A valve is installed on the infusion pipe between the first booster pump and the preparation box. The valve is used to control the flow of the drilling fluid. The drill string is coaxially fixed with the drill bit. The drill string and the drill bit are arranged in the well wall, and the well wall is opened on the surface of the wellbore.

[0013] In some preferred embodiments, the drilling fluid flow state excitation module further includes a receiving tank, a first flow rate monitor, a fixed tank, a heating plate, a supporting wall, a capillary tube, a second flow rate monitor and a second booster pump;

[0014] The first magnet is coaxially fixed to the outer circumferential surface of the drill string, and a receiving groove is provided on the outer circumferential surface of the first magnet along its axial direction, and a metal partition that can move along the receiving groove is arranged in the receiving groove, and the metal partition is initially fixed in the fixing groove, and the fixing groove is provided on the second magnet, and the second magnet is fixed to the supporting wall surface, and the second magnet is fixed to the heating plate, and the heating plate is used to change the magnetic force of the second magnet;

[0015] The capillary tube passes through the well wall and the supporting wall surface, the supporting wall surface is arranged outside the well wall, the liquid outlet of the capillary tube is sealed and fixed to and communicated with the second flow rate monitor, the inlet of the capillary tube is sealed and fixed to and communicated with the inner wall of the wellbore, and a second booster pump is arranged on the capillary tube, and the second booster pump is used to change the liquid inlet speed of the capillary tube, thereby stimulating different turbulent states of the drilling fluid;

[0016] The first flow rate monitor is fixed to the outer circumferential surface of the drill string, and is used to monitor the flow rate of the drilling fluid.

[0017] In some preferred embodiments, the gas sample injection module includes a gas tank, a third booster pump, and a gas delivery pipe;

[0018] The gas tank is used to store hydrocarbon gas, the gas tank is sealed and fixed to the inlet of the third booster pump and is in communication, the outlet of the third booster pump is sealed and fixed to one end of the gas delivery pipe and is in communication, and the other end of the gas delivery pipe is connected to the gas sample injection structure;

[0019] The gas sample injection structure comprises an annular gas inlet layer, a rock layer, a first baffle and a second baffle;

[0020] The other end of the gas supply pipe is sealed and fixed to and communicated with the annular air intake layer, and the annular air intake layer is fixed to the lower end surface of the well wall. The inner circumferential surface of the annular air intake layer is provided with a second baffle that can rotate along it, and the second baffle is fixed with multiple groups of the first baffles along the axial direction thereof, and rock layers are arranged between each pair of the first baffles. The rock layers are rock blocks with different permeabilities, and multiple rock blocks are arranged along the axial direction of the annular air intake layer.

[0021] In some preferred embodiments, the data processing module includes a degassing tank, a degasser, a chromatograph, a host display, and a recovery box;

[0022] The degassing tank is sealed and fixed to the wellbore annulus and is connected. A degasser is installed inside the degassing tank, and the degasser is used to degas the gas returning from the wellbore annulus; the chromatograph is connected to the degasser and the host display, and the chromatograph is used to perform gas measurement analysis on the gas degassed by the degasser, and the host display is used to record the gas measurement analysis data; the recovery box is used to recover the drilling fluid after degassing in the degassing tank.

[0023] In some preferred embodiments, the metal partition, the fixing groove, the second magnet, the heating plate and the capillary tube are evenly arranged in multiple groups along the axial direction of the supporting wall, and the number and size of the receiving grooves are equal to those of the fixing grooves.

[0024] In some preferred embodiments, the magnetism of the first magnet is smaller than the initial magnetism of the second magnet.

[0025] Another aspect of the present invention provides a gas logging experiment method based on the flow state of drilling fluid in a wellbore, and a simulation experiment is performed by changing the laminar flow state of the drilling fluid. Based on a gas logging experiment device based on the flow state of drilling fluid in a wellbore, the method includes the following steps:

[0026] Step S10, configuring drilling fluid in the preparation box in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the wellbore annulus, and setting the characteristic length of the wellbore annulus through the position of the metal partition; using the first increasing pump in the drilling fluid injection module to set the flow rate of the drilling fluid in the wellbore annulus; based on the original parameters, the characteristic length and the flow rate, and in combination with the Reynolds number formula, calculating the Reynolds number of the drilling fluid flowing in the wellbore annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid;

[0027] Step S20, initializing the lower critical Reynolds number, and determining whether the Reynolds number is greater than the lower critical Reynolds number; if so, changing the flow rate by the first booster pump, or changing the magnetism of the second magnet by changing the temperature of the heating plate, thereby changing the characteristic length, making the Reynolds number less than the lower critical Reynolds number, and making the drilling fluid in a laminar state;

[0028] Step S30, using the gas sample injection module to pump the gas sample into the wellbore annulus; the degasser in the gas sample injection module degasses the returned drilling fluid; after degassing, the chromatograph in the gas sample injection module performs gas testing and analysis on the degassed gas; the host display in the gas sample injection module records the gas testing data; and the drilling fluid after the gas testing and analysis is discharged into the recovery box in the gas sample injection module;

[0029] Step S40, changing the characteristic length to recalculate the Reynolds number, and jumping to step S30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step S50;

[0030] Step S50, calculating the laminar state coefficient according to the lower critical Reynolds number and multiple groups of the Reynolds numbers; arranging the multiple groups of the laminar state coefficients in ascending order and using them as the horizontal coordinates, and using the gas measurement data corresponding to the laminar state coefficients as the vertical coordinates, to establish a first change curve diagram.

[0031] The third aspect of the present invention provides a gas logging experimental method based on the flow state of drilling fluid in a wellbore, and a simulation experiment is performed by changing the turbulent state of the drilling fluid. Based on a gas logging experimental device based on the flow state of drilling fluid in a wellbore, the method comprises the following steps:

[0032] Step A10, configuring drilling fluid in the preparation box in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the wellbore annulus, and setting the characteristic length of the wellbore annulus through the position of the metal partition; using the first booster pump in the drilling fluid injection module to set the flow rate of the drilling fluid in the wellbore annulus; using the second booster pump in the drilling fluid flow state excitation module to set the liquid inlet speed of the capillary, based on the original parameters, the characteristic length, the flow rate and the liquid inlet speed, and in combination with the Reynolds number formula, calculate the Reynolds number of the drilling fluid flowing in the wellbore annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid;

[0033] Step A20, obtaining an upper critical Reynolds number corresponding to the flow rate or the liquid inlet speed, and determining whether the Reynolds number is less than the lower critical Reynolds number; if so, changing the flow rate by the first booster pump, or changing the liquid inlet speed by the second booster pump, so that the Reynolds number is greater than the upper critical Reynolds number, so that the drilling fluid is in a turbulent state;

[0034] Step A30, using the gas sample injection module to pump the gas sample into the wellbore annulus; the degasser in the gas sample injection module degasses the returned drilling fluid; after degassing, the chromatograph in the gas sample injection module performs gas testing and analysis on the degassed gas; the host display in the gas sample injection module records the gas testing data; and the drilling fluid after the gas testing and analysis is discharged into the recovery box in the gas sample injection module;

[0035] Step A40, changing the flow rate or the liquid inlet speed according to the Reynolds number, for recalculating the Reynolds number, and jumping to step A30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step A50;

[0036] Step A50, calculate the turbulence state coefficient according to the upper critical Reynolds number and multiple groups of Reynolds numbers corresponding to the upper critical Reynolds number; arrange the multiple groups of turbulence state coefficients in ascending order and use them as the horizontal coordinates, and use the gas measurement data corresponding to the turbulence state coefficients as the vertical coordinates to establish a second change curve graph.

[0037] In some preferred embodiments, the method for obtaining the upper critical Reynolds number comprises the following steps:

[0038] Step A21, injecting drilling fluid containing tracer into the wellbore annulus, setting the liquid feeding speed of the capillary tube by the second booster pump, detecting the gamma photon signal in the tracer by CT scanning, and imaging the flow morphology of the tracer in the wellbore annulus in real time on a computer;

[0039] Step A22, increasing the flow rate by the first booster pump, and when the tracer flows irregularly, intermixed, and with a tortuous and chaotic trajectory in the wellbore annulus, calculating the upper critical Reynolds number under the liquid inlet velocity condition;

[0040] Step A23, changing the liquid inlet speed by the second booster pump, jumping to step A21, when the required experiments with different liquid inlet speeds are completed, stopping the jump, and obtaining multiple groups of upper critical Reynolds numbers under different liquid inlet speed conditions.

[0041] Beneficial effects of the present invention:

[0042] The present invention can simulate laminar flow states and turbulent flow states under different conditions by setting up a drilling fluid flow state excitation module and a gas sample injection module, so that different drilling fluid flow states can be achieved in the wellbore. By setting up a data processing module, the influence of the drilling fluid flow state on the gas logging data can be analyzed, thereby improving the correction accuracy of the gas logging data under the influence of the drilling fluid flow state. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0044] Figure 1 It is a structural schematic diagram of a gas logging experimental device based on the flow state of drilling fluid in a wellbore according to the first embodiment of the present invention;

[0045] Figure 2 It is a cross-sectional view of a wellbore structure in a gas logging experimental device based on the flow state of drilling fluid in a wellbore according to the first embodiment of the present invention;

[0046] Figure 3 yes Figure 2 A top view of

[0047] Figure 4 It is a cross-sectional view of a gas sample injection structure in a gas logging experimental device based on the flow state of drilling fluid in a wellbore according to the first embodiment of the present invention;

[0048] Figure 5 yes Figure 4 A top view of

[0049] Figure 6 It is a schematic diagram of a first change curve of a gas logging experimental method based on the flow state of drilling fluid in a wellbore according to the second embodiment of the present invention;

[0050] Figure 7 It is a schematic diagram of a second change curve of a gas logging experimental method based on the flow state of drilling fluid in a wellbore according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0051] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0052] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] The first embodiment of the present invention, see Figure 1-Figure 5 , provides a gas logging experimental device based on the flow state of drilling fluid in a wellbore, the device includes a drilling fluid injection module, a drilling fluid flow state excitation module, a gas sample injection module, and a data processing module;

[0054] The drilling fluid injection module is used to inject drilling fluid into the wellbore annulus;

[0055] The drilling fluid flow state excitation module includes a first magnet 51, a second magnet 83 and a metal partition 81 connected to the drilling fluid injection module; based on the magnetic force of the first magnet 51 and the second magnet 83, the metal partition 81 is moved to excite the laminar or turbulent drilling fluid flow state;

[0056] The gas sample injection module is fixed below the drilling fluid flow state excitation module, and is used to change the permeability of the rock formation 142 through the gas sample injection structure 14, and to simulate the uniform gas intake process of the gas sample along the wellbore, thereby simulating the process of hydrocarbon gas infiltration into the wellbore annulus;

[0057] The data processing module is connected to the drilling fluid flow state excitation module, and the data processing module is used to perform gas measurement analysis, degassing and recovery processing on the returned drilling fluid.

[0058] For further explanation of the present invention, see Figure 1 The drilling fluid injection module includes a preparation box 1, a valve 2, a fluid delivery pipe 3, a first booster pump 4, a drill string 5, a drill bit 6 and a well wall 8;

[0059] The preparation box 1 is used to prepare and store drilling fluid. The preparation box 1 is sealed and fixed to and connected with one end of the infusion pipe 3. The other end of the infusion pipe 3 is arranged in the drill string 5 through the first booster pump 4. A valve 2 is installed on the infusion pipe 3 between the first booster pump 4 and the preparation box 1. The valve 2 is used to control the flow of the drilling fluid. The drill string 5 is coaxially fixed with the drill bit 6. The drill string 5 and the drill bit 6 are arranged in the well wall 8, and the well wall 8 is opened on the surface of the wellbore.

[0060] For further explanation of the present invention, see Figure 1-Figure 3 The drilling fluid flow state excitation module further includes a receiving tank 52, a first flow rate monitor 7, a fixed tank 82, a heating plate 84, a supporting wall 85, a capillary 86, a second flow rate monitor 9 and a second booster pump 10;

[0061] The first magnet 51 is coaxially fixed to the outer circumferential surface of the drill string 5. The outer circumferential surface of the first magnet 51 is provided with a receiving groove 52 along its axial direction. The receiving groove 52 is used to arrange a metal partition 81 that can move along the receiving groove. The metal partition 81 is initially fixed in the fixing groove 82. The fixing groove 82 is provided on the second magnet 83. The second magnet 83 is fixed to the supporting wall 85. The second magnet 83 is fixed to the heating plate 84. The heating plate 84 is used to change the magnetic force of the second magnet 83.

[0062] The capillary tube 86 passes through the well wall 8 and the supporting wall 85, and the supporting wall 85 is arranged outside the well wall 8. The liquid outlet of the capillary tube 86 is sealed and fixed to and communicated with the second flow rate monitor 9, and the inlet of the capillary tube 86 is sealed and fixed to and communicated with the inner wall of the wellbore. The capillary tube 86 is provided with a second booster pump 10, and the second booster pump 10 is used to change the liquid inlet speed of the capillary tube 86, so as to stimulate different turbulent states of the drilling fluid;

[0063] The first flow rate monitor 7 is fixed to the outer circumferential surface of the drill string 5, and the first flow rate monitor 7 is used to monitor the flow rate of the drilling fluid.

[0064] The annular volume between the drill string 5 and the wellbore wall 8 is defined as the wellbore annulus.

[0065] For further explanation of the present invention, see Figure 1 , Figure 4 , Figure 5 The gas sample injection module includes a gas tank 11, a third booster pump 12, and a gas delivery pipe 13;

[0066] The gas tank 11 is used to store hydrocarbon gas. The gas tank 11 is sealed and fixed to the inlet of the third booster pump 12 and is in communication with each other. The outlet of the third booster pump 12 is sealed and fixed to one end of the gas delivery pipe 13 and is in communication with each other. The other end of the gas delivery pipe 13 is connected to the gas sample injection structure 14.

[0067] The gas sample injection structure 14 includes an annular gas inlet layer 141, a rock layer 142, a first baffle 144 and a second baffle 145;

[0068] The other end of the gas supply pipe 13 is sealed and fixed to and communicated with the annular air intake layer 141, and the annular air intake layer 141 is fixed to the lower end surface of the well wall 8. The inner circumferential surface of the annular air intake layer 141 is provided with a second baffle 145 that can rotate along it, and the second baffle 145 is fixed with multiple groups of the first baffles 144 along the axial direction thereof, and rock layers 142 are provided between each pair of the first baffles 144. The rock layers 142 are rock blocks 143 with different permeabilities, and multiple rock blocks 143 are provided along the axial direction of the annular air intake layer 141.

[0069] For further explanation of the present invention, see Figure 1 , the data processing module includes a degassing tank 15, a degasser 16, a chromatograph 17, a host display 18 and a recovery box 19;

[0070] The degassing tank 15 is sealed and fixed to the borehole annulus and is connected. A degasser 16 is installed inside the degassing tank 15. The degasser 16 is used to degas the gas returning from the borehole annulus. The chromatograph 17 is connected to the degasser 16 and the host display 18. The chromatograph 17 is used to perform gas measurement analysis on the gas degassed by the degasser 16. The host display 18 is used to record the gas measurement analysis data. The recovery box 19 is used to recover the degassed drilling fluid in the degassing tank 15.

[0071] For further explanation of the present invention, see Figure 3 The metal partition 81, the fixed groove 82, the second magnet 83, the heating plate 84 and the capillary tube 86 are evenly arranged in multiple groups along the axial direction of the support wall 85, and the number and size of the receiving grooves 52 are equal to those of the fixed grooves 82.

[0072] For further explanation of the present invention, see Figure 3 , the magnetism of the first magnet 51 is smaller than the initial magnetism of the second magnet 83 .

[0073] The second embodiment of the present invention, see Figure 1-Figure 5 , Figure 6 , provides a gas logging experimental method based on the flow state of drilling fluid in a wellbore, and performs a simulation experiment by changing the laminar flow state of the drilling fluid. Based on a gas logging experimental device based on the flow state of drilling fluid in a wellbore, the method includes the following steps:

[0074] Step S10, configuring drilling fluid in the preparation box 1 in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the wellbore annulus, setting the characteristic length of the wellbore annulus through the position of the metal partition 81; using the first increase pump 4 in the drilling fluid injection module to set the flow rate of the drilling fluid in the wellbore annulus; based on the original parameters, the characteristic length and the flow rate, and in combination with the Reynolds number formula, calculating the Reynolds number of the drilling fluid flowing in the wellbore annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid;

[0075] Step S20, initializing the lower critical Reynolds number, determining whether the Reynolds number is greater than the lower critical Reynolds number; if so, changing the flow rate by the first booster pump 4, or changing the magnetism of the second magnet 83 by changing the temperature of the heating plate 84, thereby changing the characteristic length, making the Reynolds number less than the lower critical Reynolds number, and making the drilling fluid in a laminar state;

[0076] Step S30, using the gas sample injection module to pump the gas sample into the wellbore annulus; the degasser 16 in the gas sample injection module degasses the returned drilling fluid; after degassing, the chromatograph 17 in the gas sample injection module performs gas measurement analysis on the degassed gas; the host display 18 in the gas sample injection module records the gas measurement data; and the drilling fluid after the gas measurement analysis is discharged into the recovery box 19 in the gas sample injection module;

[0077] Step S40, changing the characteristic length to recalculate the Reynolds number, and jumping to step S30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step S50;

[0078] Step S50, calculating the laminar state coefficient according to the lower critical Reynolds number and multiple groups of the Reynolds numbers; arranging the multiple groups of the laminar state coefficients in ascending order and using them as the horizontal coordinates, and using the gas measurement data corresponding to the laminar state coefficients as the vertical coordinates, to establish a first change curve diagram.

[0079] Wherein, the Reynolds number is calculated as follows:

[0080]

[0081] Among them, R e is the Reynolds number, dimensionless; ρ is the density of the drilling fluid, in kg / m 3 ; v is the flow rate of drilling fluid in the wellbore annulus, unit is m / s; d is the characteristic length of the wellbore annulus, unit is m; μ is the dynamic viscosity coefficient of drilling fluid, unit is N·s / m 2 .

[0082] Among them, the lower critical Reynolds number is fixed at 2300.

[0083] Wherein, the laminar flow state coefficient L is calculated as follows:

[0084] L=R ec下 / R e , the R ec下 is the lower critical Reynolds number; different L indicates different laminar flow states, and the larger L is, the more stable the laminar flow is.

[0085] Among them, the method of "changing the characteristic length" is to change the annulus volume and the annulus surface area by changing the number of connections between the metal partition 81 and the receiving groove 52, thereby changing the characteristic length (characteristic length = annulus volume / annulus surface area).

[0086] In this embodiment, the drilling fluid density ρ is obtained to be 1200 kg / m 3 , the dynamic viscosity coefficient of drilling fluid is 0.036N·s / m 2 , the drilling fluid velocity v in the borehole annulus is 1m / s, the inner diameter of the borehole annulus is 63.5mm, and the outer diameter of the borehole annulus is 88.9mm. The characteristic length d of the borehole annulus is calculated by using the inner diameter and outer diameter of the borehole annulus to be 0.0762m. The Reynolds number R is calculated. e is 1270; determine the laminar flow state, i.e. R e =1270<R ec下 =2300 is laminar flow state; inject 0.6L of 10% mixed gas sample into the wellbore annulus for gas logging analysis; calculate the laminar flow state coefficient L under the above conditions to be 1.81, and obtain the gas logging data T under the corresponding conditions g ; Adjust the drilling fluid velocity v and the characteristic length d of the wellbore annulus to achieve different laminar flow states (L = 2.58, 2.20, 1.51, 1.21), and obtain the gas measurement data T under the corresponding conditions g ; Get gas measurement data T g The curve graph with the change of laminar flow state coefficient L (L = 2.58, 2.20, 1.81, 1.51, 1.21) is the first change curve graph. Figure 6 As shown, as the laminar flow state coefficient increases (the more stable the laminar flow), the total hydrocarbon detection value decreases accordingly.

[0087] The third embodiment of the present invention, see Figure 1-Figure 5 , Figure 7 A gas logging experimental method based on the flow state of drilling fluid in a wellbore is proposed. A simulation experiment is performed by changing the turbulent state of the drilling fluid. Based on a gas logging experimental device based on the flow state of drilling fluid in a wellbore, the method includes the following steps:

[0088] Step A10, configuring drilling fluid in the preparation box 1 in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the wellbore annulus, setting the characteristic length of the wellbore annulus through the position of the metal partition 81; using the first booster pump 4 in the drilling fluid injection module to set the flow rate of the drilling fluid in the wellbore annulus; using the second booster pump 10 in the drilling fluid flow state excitation module to set the liquid inlet speed of the capillary 86, based on the original parameters, the characteristic length, the flow rate and the liquid inlet speed, and in combination with the Reynolds number formula, calculate the Reynolds number of the drilling fluid flowing in the wellbore annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid;

[0089] Step A20, obtaining an upper critical Reynolds number corresponding to the flow rate or the liquid inlet speed, and determining whether the Reynolds number is less than the lower critical Reynolds number; if so, changing the flow rate by the first booster pump 4, or changing the liquid inlet speed by the second booster pump 10, so that the Reynolds number is greater than the upper critical Reynolds number, so that the drilling fluid is in a turbulent state;

[0090] Step A30, using the gas sample injection module to pump the gas sample into the wellbore annulus; the degasser 16 in the gas sample injection module degasses the returned drilling fluid; after degassing, the chromatograph 17 in the gas sample injection module performs gas measurement analysis on the degassed gas; the host display 18 in the gas sample injection module records the gas measurement data; and the drilling fluid after the gas measurement analysis is discharged into the recovery box 19 in the gas sample injection module;

[0091] Step A40, changing the flow rate or the liquid inlet speed according to the Reynolds number, for recalculating the Reynolds number, and jumping to step A30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step A50;

[0092] Step A50, calculate the turbulence state coefficient according to the upper critical Reynolds number and multiple groups of Reynolds numbers corresponding to the upper critical Reynolds number; arrange the multiple groups of turbulence state coefficients in ascending order and use them as the horizontal coordinates, and use the gas measurement data corresponding to the turbulence state coefficients as the vertical coordinates to establish a second change curve graph.

[0093] Among them, the method for changing the flow rate or changing the liquid inlet speed is, in this embodiment, changing the flow rate or changing the liquid inlet speed according to the required Reynolds number (such as: 3564, 3117, 2743).

[0094] The calculation method of the Reynolds number refers to the method of the second embodiment.

[0095] Among them, the turbulence state coefficient T is calculated as follows:

[0096] T=R e / R ec上 ;

[0097] Among them, R ec上 is the upper critical Reynolds number; different T indicates different turbulent states, and the larger T is, the more turbulent the turbulence is.

[0098] Wherein, the tracer is 133 xenon.

[0099] In this embodiment, the drilling fluid density ρ is obtained to be 1200 kg / m 3 , the dynamic viscosity coefficient of drilling fluid is 0.036N·s / m 2 , the drilling fluid velocity v in the borehole annulus is 3m / s, the borehole annulus inner diameter is 63.5mm, the borehole annulus outer diameter is 88.9mm, the capillary liquid velocity v′ is set to 1m / s, and the borehole annulus inner diameter and borehole annulus outer diameter are used to calculate the borehole annulus characteristic length d to be 0.0762m, and the Reynolds number R is calculated. e is 3810; obtain the upper critical Reynolds number R of different capillary liquid inlet speeds ec上 The experiment shows that the upper critical Reynolds numbers are 3564, 3117, and 2743 when the liquid inlet speed of the capillary is 1m / s, 1.5m / s, and 2m / s, respectively; the turbulent state, i.e., R e =3810>R ec上 =3564 is a turbulent state; inject 0.6L of 10% mixed gas sample into the wellbore annulus for gas logging analysis; calculate the turbulent state coefficient T under the above conditions to be 1.07, and obtain the gas logging data T under the corresponding conditions g ; Adjust the drilling fluid flow rate v and the capillary fluid inlet speed v′ to achieve different turbulent states (T = 1.22, 1.38, 1.53, 1.67), and obtain the gas measurement data T under the corresponding conditions g ; Get gas measurement data T g The curve graph with the change of turbulence state coefficient T (T = 1.07, 1.22, 1.38, 1.53, 1.67), that is, the second change curve graph, is as follows: Figure 7 As shown, as the turbulence state coefficient increases (the more turbulent the turbulence), the total hydrocarbon detection value increases accordingly.

[0100] Preferably, the method for obtaining the upper critical Reynolds number comprises the following steps:

[0101] Step A21, injecting drilling fluid containing tracer into the wellbore annulus, setting the liquid feeding speed of the capillary 86 by the second booster pump 10, detecting the gamma photon signal in the tracer by CT scanning, and imaging the flow morphology of the tracer in the wellbore annulus in real time in a computer;

[0102] Step A22, increasing the flow rate by the first booster pump 4, and when the tracer flows irregularly, intermixed, and with a tortuous and chaotic trajectory in the wellbore annulus, calculating the upper critical Reynolds number under the liquid inlet velocity condition;

[0103] Step A23, changing the liquid inlet speed by the second booster pump 10, jumping to step A21, when the required experiments with different liquid inlet speeds are completed, stopping the jump, and obtaining multiple groups of upper critical Reynolds numbers under different liquid inlet speed conditions.

[0104] The terms "first", "second", etc. are used to distinguish similar objects rather than to describe or indicate a particular order or sequence.

[0105] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0106] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A gas logging experimental device based on the flow state of drilling fluid in a wellbore, characterized in that: The device includes a drilling fluid injection module, a drilling fluid flow state excitation module, a gas sample injection module, and a data processing module; The drilling fluid injection module is used to inject drilling fluid into the wellbore annulus; The drilling fluid flow state excitation module comprises a first magnet (51), a second magnet (83) and a metal partition (81) connected to the drilling fluid injection module; based on the magnetic force of the first magnet (51) and the second magnet (83), the metal partition (81) is moved to excite the laminar or turbulent drilling fluid flow state; The gas sample injection module is fixed below the drilling fluid flow state excitation module, and is used to change the permeability of the rock formation (142) through the gas sample injection structure (14), and is used to simulate the uniform gas intake process of the gas sample along the wellbore, thereby simulating the process of hydrocarbon gas infiltration into the wellbore annulus; The data processing module is connected to the drilling fluid flow state excitation module, and the data processing module is used to perform gas measurement analysis, degassing and recovery processing on the returned drilling fluid.

2. A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to claim 1, characterized in that: The drilling fluid injection module comprises a preparation box (1), a valve (2), a fluid delivery pipe (3), a first booster pump (4), a drill string (5), a drill bit (6) and a well wall (8); The preparation box (1) is used for preparing and storing drilling fluid. The preparation box (1) is sealed and fixed to one end of the fluid delivery pipe (3) and is in communication. The other end of the fluid delivery pipe (3) is arranged in the drill string (5) through a first booster pump (4). A valve (2) is installed on the fluid delivery pipe (3) between the first booster pump (4) and the preparation box (1). The valve (2) is used for controlling the flow of the drilling fluid. The drill string (5) is coaxially fixed with the drill bit (6). The drill string (5) and the drill bit (6) are arranged in the well wall (8). The well wall (8) is opened on the surface of the wellbore.

3. A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to claim 2, characterized in that: The drilling fluid flow state excitation module also includes a receiving tank (52), a first flow rate monitor (7), a fixed tank (82), a heating plate (84), a supporting wall (85), a capillary (86), a second flow rate monitor (9) and a second booster pump (10); The first magnet (51) is coaxially fixed to the outer circumferential surface of the drill string (5); the outer circumferential surface of the first magnet (51) is provided with a receiving groove (52) along its axial direction; the receiving groove (52) is used to arrange a metal partition (81) that can move along the receiving groove; the metal partition (81) is fixed in the fixing groove (82) in an initial state; the fixing groove (82) is provided on the second magnet (83); the second magnet (83) is fixed to the supporting wall (85); the second magnet (83) is fixed to the heating plate (84); the heating plate (84) is used to change the magnetic force of the second magnet (83); The capillary tube (86) passes through the well wall (8) and the supporting wall surface (85), the supporting wall surface (85) is arranged outside the well wall (8), the liquid outlet of the capillary tube (86) is sealed and fixed to and communicated with the second flow rate monitor (9), the inlet of the capillary tube (86) is sealed and fixed to and communicated with the inner wall of the wellbore, and a second booster pump (10) is arranged on the capillary tube (86), and the second booster pump (10) is used to change the liquid inlet speed of the capillary tube (86), thereby stimulating different turbulent states of the drilling fluid; The first flow rate monitor (7) is fixed to the outer circumferential surface of the drill string (5), and the first flow rate monitor (7) is used to monitor the flow rate of the drilling fluid.

4. A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to claim 3, characterized in that: The gas sample injection module comprises a gas tank (11), a third booster pump (12), and a gas delivery pipe (13); The gas tank (11) is used to store hydrocarbon gas. The gas tank (11) is sealed and fixed to the inlet of the third booster pump (12) and is in communication with each other. The outlet of the third booster pump (12) is sealed and fixed to one end of the gas delivery pipe (13) and is in communication with each other. The other end of the gas delivery pipe (13) is connected to the gas sample injection structure (14). The gas sample injection structure (14) comprises an annular gas inlet layer (141), a rock layer (142), a first baffle (144) and a second baffle (145); The other end of the gas delivery pipe (13) is sealed and fixed to and communicates with the annular air intake layer (141); the annular air intake layer (141) is fixed to the lower end surface of the well wall (8); the inner circumferential surface of the annular air intake layer (141) is provided with a second baffle (145) that can rotate along the inner circumferential surface; the second baffle (145) is fixed with multiple groups of the first baffles (144) along the axial direction thereof; rock layers (142) are provided between each pair of the first baffles (144); the rock layers (142) are rock blocks (143) with different permeabilities; multiple rock blocks (143) are provided along the axial direction of the annular air intake layer (141).

5. The gas logging experimental device based on the flow state of drilling fluid in the wellbore according to claim 4, characterized in that: The data processing module comprises a degassing tank (15), a degasser (16), a chromatograph (17), a host display (18) and a recovery box (19); The degassing tank (15) is sealed and fixed to the wellbore annulus and is connected. A degasser (16) is installed inside the degassing tank (15). The degasser (16) is used to degas the gas returning from the wellbore annulus. The chromatograph (17) is connected to the degasser (16) and the host display (18). The chromatograph (17) is used to perform gas measurement analysis on the gas degassed by the degasser (16). The host display (18) is used to record the gas measurement analysis data. The recovery box (19) is used to recover the drilling fluid after degassing in the degassing tank (15).

6. A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to claim 5, characterized in that: The metal partition (81), the fixing groove (82), the second magnet (83), the heating plate (84) and the capillary tube (86) are evenly arranged in multiple groups along the axial direction of the supporting wall (85), and the number and size of the receiving grooves (52) are equal to those of the fixing grooves (82).

7. A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to claim 6, characterized in that: The magnetism of the first magnet (51) is smaller than the initial magnetism of the second magnet (83).

8. A gas logging experiment method based on the flow state of drilling fluid in a wellbore, which performs a simulation experiment by changing the laminar flow state of the drilling fluid, characterized in that: A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to any one of claims 1 to 7, characterized in that the method comprises the following steps: Step S10, preparing drilling fluid in the preparation box (1) in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the wellbore annulus, and setting the characteristic length of the wellbore annulus through the position of the metal partition (81); using the first increasing pump (4) in the drilling fluid injection module to set the flow rate of the drilling fluid in the wellbore annulus; based on the original parameters, the characteristic length and the flow rate, and in combination with the Reynolds number formula, calculating the Reynolds number of the drilling fluid flowing in the wellbore annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid; Step S20, initializing the lower critical Reynolds number, determining whether the Reynolds number is greater than the lower critical Reynolds number; if so, changing the flow rate by means of the first booster pump (4), or changing the magnetism of the second magnet (83) by changing the temperature of the heating plate (84), thereby changing the characteristic length, making the Reynolds number less than the lower critical Reynolds number, and making the drilling fluid in a laminar state; Step S30, using the gas sample injection module to pump the gas sample into the wellbore annulus; using the degasser (16) in the gas sample injection module to degas the returned drilling fluid; after the degassing treatment, using the chromatograph (17) in the gas sample injection module to perform gas measurement analysis on the degassed gas; and using the host display (18) in the gas sample injection module to record the gas measurement data; and discharging the drilling fluid after the gas measurement analysis into the recovery box (19) in the gas sample injection module; Step S40, changing the characteristic length to recalculate the Reynolds number, and jumping to step S30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step S50; Step S50, calculating the laminar state coefficient according to the lower critical Reynolds number and multiple groups of the Reynolds numbers; arranging the multiple groups of the laminar state coefficients in ascending order and using them as the horizontal coordinates, and using the gas measurement data corresponding to the laminar state coefficients as the vertical coordinates, to establish a first change curve diagram.

9. A gas logging experiment method based on the flow state of drilling fluid in a wellbore, which performs a simulation experiment by changing the turbulent state of the drilling fluid, characterized in that: A gas logging experimental device based on the flow state of drilling fluid in a wellbore according to any one of claims 1 to 7, characterized in that the method comprises the following steps: Step A10, preparing drilling fluid in the preparation box (1) in the drilling fluid injection module, and obtaining the original parameters of the drilling fluid; injecting the drilling fluid into the borehole annulus, and setting the characteristic length of the borehole annulus through the position of the metal partition (81); using the first booster pump (4) in the drilling fluid injection module to set the flow rate of the drilling fluid in the borehole annulus; using the second booster pump (10) in the drilling fluid flow state excitation module to set the liquid inlet speed of the capillary (86), based on the original parameters, the characteristic length, the flow rate and the liquid inlet speed, and in combination with the Reynolds number formula, calculate the Reynolds number of the drilling fluid flowing in the borehole annulus; the original parameters include the density and dynamic viscosity coefficient of the drilling fluid; Step A20, obtaining an upper critical Reynolds number corresponding to the flow rate or the liquid inlet speed, and determining whether the Reynolds number is less than the lower critical Reynolds number; if so, changing the flow rate by means of the first booster pump (4), or changing the liquid inlet speed by means of the second booster pump (10), so that the Reynolds number is greater than the upper critical Reynolds number, and the drilling fluid is in a turbulent state; Step A30, using the gas sample injection module to pump the gas sample into the wellbore annulus; using the degasser (16) in the gas sample injection module to degas the returned drilling fluid; after the degassing treatment, using the chromatograph (17) in the gas sample injection module to perform gas measurement analysis on the degassed gas; and using the host display (18) in the gas sample injection module to record the gas measurement data; and discharging the drilling fluid after the gas measurement analysis into the recovery box (19) in the gas sample injection module; Step A40, changing the flow rate or the liquid inlet speed according to the Reynolds number, for recalculating the Reynolds number, and jumping to step A30 to obtain multiple groups of gas measurement data corresponding to the Reynolds number; when the number of repeated experimental groups reaches the required number of experimental groups, the process ends and jumps to step A50; Step A50, calculate the turbulence state coefficient according to the upper critical Reynolds number and multiple groups of Reynolds numbers corresponding to the upper critical Reynolds number; arrange the multiple groups of turbulence state coefficients in ascending order and use them as the horizontal coordinates, and use the gas measurement data corresponding to the turbulence state coefficients as the vertical coordinates to establish a second change curve graph.

10. A gas logging experimental method based on the flow state of drilling fluid in a wellbore according to claim 9, characterized in that: The method for obtaining the upper critical Reynolds number comprises the following steps: Step A21, injecting drilling fluid containing a tracer into the wellbore annulus, setting the liquid feeding speed of the capillary (86) by the second booster pump (10), detecting the gamma photon signal in the tracer by CT scanning, and imaging the flow morphology of the tracer in the wellbore annulus in real time on a computer; Step A22, increasing the flow rate by the first booster pump (4), and when the tracer flows irregularly, intermixed, and with a tortuous and chaotic trajectory in the wellbore annulus, calculating the upper critical Reynolds number under the liquid inlet velocity condition; Step A23, changing the liquid inlet speed by the second booster pump (10), jumping to step A21, when the required experiments with different liquid inlet speeds are completed, stopping the jump, and obtaining multiple groups of upper critical Reynolds numbers under different liquid inlet speed conditions.

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